Let's determine the number of valence electrons for each of the given elements, 5 (Boron), 3 (Lithium), 15 (Phosphorus), and 8 (Oxygen).
1. Element with atomic number 5: Boron
- Boron has an atomic number of 5, meaning it has 5 electrons.
- The electron configuration of Boron is [tex]\(1s^2 2s^2 2p^1\)[/tex].
- The last shell (second shell) has 2 (s) + 1 (p) = 3 valence electrons.
2. Element with atomic number 3: Lithium
- Lithium has an atomic number of 3, meaning it has 3 electrons.
- The electron configuration of Lithium is [tex]\(1s^2 2s^1\)[/tex].
- The last shell (second shell) has 1 valence electron.
3. Element with atomic number 15: Phosphorus
- Phosphorus has an atomic number of 15, meaning it has 15 electrons.
- The electron configuration of Phosphorus is [tex]\(1s^2 2s^2 2p^6 3s^2 3p^3\)[/tex].
- The last shell (third shell) has 2 (s) + 3 (p) = 5 valence electrons.
4. Element with atomic number 8: Oxygen
- Oxygen has an atomic number of 8, meaning it has 8 electrons.
- The electron configuration of Oxygen is [tex]\(1s^2 2s^2 2p^4\)[/tex].
- The last shell (second shell) has 2 (s) + 4 (p) = 6 valence electrons.
Hence, the number of valence electrons for each element is:
- Boron (5): 3 valence electrons
- Lithium (3): 1 valence electron
- Phosphorus (15): 5 valence electrons
- Oxygen (8): 6 valence electrons
So, the final result is:
- Boron: 3
- Lithium: 1
- Phosphorus: 5
- Oxygen: 6
